Three months after Dispatches: Undercover Mosque won a police apology and libel damages, Channel 4 has announced it is returning to the subject in Undercover Mosque: The Return.

Earlier this year West Midlands police and the Crown Prosecution Service paid out a six-figure sum to Channel 4 and Undercover Mosque Hardcash, the independent producer responsible for the documentary, after falsely accusing the programme of misleading viewers.

The documentary, an undercover investigation into extremism in mainstream British mosques, featured preachers calling for homosexuals to be killed, espousing male supremacy, condemning non-Muslims and predicting jihad.

Last August, West Midlands police referred the critically acclaimed programme to media regulator Ofcom and, in conjunction with the CPS, issued a statement saying the words of three preachers featured had been "heavily edited" so their meaning was "completely distorted".

However, Ofcom cleared Channel 4 and Hardcash of any TV fakery and ruled they "dealt with the subject matter responsibly and in context".

The two companies subsequently launched their libel action.

It has now emerged that the same Hardcash production team have revisited the subject to "see whether extremist beliefs continue to be promoted in certain key British Muslim institutions".

In the new documentary, a female reporter attends prayer meetings at an important British mosque which claims to be dedicated to moderation and "dialogue with other faiths".

According to Channel 4, "she secretly films sermons given to the women-only congregation in which female preachers recite extremist and intolerant beliefs".

In one scene, as hundreds of women and some children come to pray, a preacher calls for adulterers, homosexuals, women who act like men and Muslim converts to other faiths to be killed, saying: "Kill him, kill him. You have to kill him, you understand. This is Islam."

Channel 4 also said that in the same mosque, "the reporter visits the bookshop and discovers books and DVDs still on sale, promoting extremist, anti-Semitic, misogynistic and intolerant messages".

The undercover reporter also "films inside a key Saudi-funded Muslim organisation, which claims to promote tolerance and integration yet distributes literature which promotes intolerance for non-Muslims, an extreme version of sharia law and teachings which support discrimination against women".

In addition, Undercover Mosque: The Return also "investigates the role of the Saudi Arabian religious establishment in spreading a hard-line, fundamentalist Islamic ideology in the UK - the very ideology the government claims to be tackling".

A former Foreign Office minister tells Dispatches he thinks the government should take a stronger line on the issue.

The film also includes interviews with Islamic academics who condemn messages of intolerance and segregation and warn of the impact they will have on British society.

Dispatches: Undercover Mosque: The Return will air on Channel 4 on September 1 at 8pm.

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